CBSE Chemistry Experiment Melting Point of Ice and Boiling Point of Water

While boiling the water, the water begins to warm up as the temperature rises slowly because the kinetic energy is rising at the same time. The intermolecular distance surrounding the water molecules continues expanding due to this increase in kinetic energy, and the molecules can now move about more freely. When the temperature reaches a specific point, the intermolecular space expands to the point where the water molecules separate from one another and vaporize. This explains the boiling point temperatures of the water. Ice (solid), water (a liquid), and gas (vapour) are all different states of the element water. 

Table of Content

• Introduction

• Aim

• Procedure

• Result

Aim

To determine the water's boiling point and the melting point of ice.

Apparatus Required

• Ice

• Beaker

• Wire gauze

• Burner

• Thermometer

• Clamp stand

• Tripod Stand

• Boiling tube

Theory

The melting point decreases when the pressure increases, and the boiling point increases when the pressure increases. The ice melting point is 0 °C, meaning that at that temperature, the forces of contact between the molecules of solid H20 can be melted, turning the ice into water. Since there are fewer forces of interaction in the liquid form, water is a liquid at ambient temperature. Water has a boiling point of 100 °C, which means that at sea level, the water's vapour pressure equals the air pressure at this temperature.

The heat energy known as latent heat of fusion is acquired during ice melting and is preserved in the water produced. Latent heat of fusion is defined as the amount of heat energy needed to transform 1 kilogram of a solid into a liquid at its melting point.

Procedure

To Determine the Boiling Point of Water Experiment

• Add a couple of pumice stones to a boiling tube of 25–30 ml of water. 

• As illustrated in the boiling tube diagram below, attach and set the thermometer atop the water in the boiling tube and note the temperature. 

• Underneath the boiling tube, place a Bunsen burner. Measure and record the temperature until the water boils.

Boiling Tube 

To Determine the Melting Point of Ice Experiment

• In a beaker, load it's half using distilled water-derived dried crushed ice. 

• Drop a thermometer off the clamp stand so that the ice entirely encircles the thermometer bulb. 

• Observe and record the thermometer readings per 1 min until the ice dissolves.

The melting point apparatus diagram is provided below:

Melting Point Apparatus

Observations

Result

• The melting point of ice is 0℃

• The boiling point of water is 100℃

• The temperature stays steady once the ice melting process starts and the boiling point is attained.

Precautions

• While heating or boiling, utilize a proper clamp stand. Boil the water by rotating the flame.

• The thermometer's bulb needs to be just barely above the water or ice.

• Pick a thermometer of higher calibre with an easily interpretable calibrated scale. The sides of the boiling tube or beaker must not be touched by the thermometer.

Lab Manual Questions

1. Why is mercury an excellent thermometer material?

Ans: Mercury in a liquid condition at normal temperature possesses the maximum expansion coefficient. Thus, even a small shift in temperature is noticeable. 

2. Why are pumice stones added while boiling water?

Ans: While boiling water, energy is released in the form of bubbles. If no bubbles appear, the water could be too hot and explode. 

3. To determine the boiling point, why do we place a two-holed cork in the flask with a rounded bottom?

Ans: To enable the steam to exit the flask because if it doesn't, the rounded bottom flask could explode due to excessive internal pressure. 

4. Why does the thermometer bulb placed on top of the water's surface for estimating the water's boiling point?

Ans: To determine accurate water’s boiling point since steam simply comprises water vapour, and any non-volatile impurities that may exist in the water will have no effect.

Viva Questions

1. Define melting point?

Ans: The point at which the substance shifts from solid to liquid.

2. Define boiling point?

Ans: The temperature at which a liquid’s vapour pressure equals the gas pressure.

3. Who invented the thermometer?

Ans: Daniel Gabriel Fahrenheit

4. Thermometer is said to be accurate if Fahrenheit shows

Ans: 32oF

5. Why do individuals spray NaCl on Ice in colder regions?

Ans: The melting of ice is easier.

6. What is the relationship between boiling point and vapour pressure?

Ans: Inversely proportional.

7. Why does ice float on water?

Ans: Water has a higher density compared to ice.

8. The density of water is maximum at

Ans: 4oC

9. In laboratories to determine the boiling point of water, which type of water is used

Ans: distilled water

10. Steam or water, which possesses higher heat energy?

Ans: steam

Practical Based Questions

1. What is the boiling point of impure or hard water?

1. 100oC

2. Above 100oC

3. Below 100oC

4. Neither of the three option

Ans: The boiling point of impure or hard water is above 100oC.

2. What is the boiling point of pure water in Kelvin?

1. 373.15K

2. 273.15K

3. 243K

4. 173.15K

Ans: The boiling point of pure water in kelvin 373.15K.

3. What is the melting point of pure water in Kelvin?

1.  373K

2. 273K

3. 243K

4. 173K

Ans: The melting point of pure water in kelvin is 273 K.

4. When a thermometer is taken from the melting ice to the water which is warm, (2/5) th of the space connecting the upper and bottom point sets is reached by the mercury level. What is the water's temperature?

1. 217K

2. 220K

3. 313.15K

4. 330K

Ans: The temperature of water is 313.15K

5. Why does the temperature of the ice not increase when heated constantly?

1. Heat goes out of the system

2. Heat is not used

3. Formation of latent heat

4. Heat remains inside the system

Ans: The temperature of ice does not increase when heated constantly due to the formation of latent heat.

6. There are 20 splits between 10 °C and 20 °C on a thermometer. What is the thermometer's lowest count?

1. 0.5

2. 0.1

3. 1

4. 2

Ans: The thermometer's lowest count is 0.5.

7. When NaCl is added to the water what happens to the boiling point of water?

1. Increases

2. Decreases

3. Remains constant

4. None of the three option

Ans: When NaCl is added to the water the boiling point of the water increases.

8. What is the boiling point of water in hill stations?

1. 100o C

2. Less than 100o C

3. Greater than 100oC

4. None of the three option

Ans: The boiling point of water in hill stations is less than 100oC.

9. In the chemistry labs, which of the following will be chosen to determine the melting point of  ice?

1. Slab of ice

2. Dry crushed cubes of ice 

3. Ice cubes

4. Ice cubes added to the water

Ans: In chemistry labs dry crushed cubes of ice will be chosen to determine the melting point of ice.

10. At what temperature does Ice and water co-exist in atmospheric pressure?

1. 0o C

2. Below 0o C

3. Above 0o C

4. None of the three option

Ans: The ice and water co-exist in atmospheric temperature at 0o C.

Conclusion

This chemistry experiment article helps to determine the melting point of ice and boiling point of water with a simple and easy procedure. The solid and liquid phases are in equilibrium at the melting point. A particle's melting point is often reported at a standard pressure because it relies on pressure. The temperature where the water turns into a vapour and the pressure of the surrounding air equals that of the water is known as the boiling point of water. This experiment verifies the melting point of ice is 0℃ and the boiling point of water is 100℃